/*
 * Copyright  2002-2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package com.izforge.izpack.util.file.types.selectors;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import com.izforge.izpack.api.data.InstallData;
import com.izforge.izpack.util.file.types.Parameter;

/**
 * Selector that filters files based on whether they contain a
 * particular string.
 */
public class ContainsSelector extends BaseExtendSelector
{

    private String contains = null;
    private boolean casesensitive = true;
    private boolean ignorewhitespace = false;
    /**
     * Key to used for parameterized custom selector
     */
    public static final String EXPRESSION_KEY = "expression";
    /**
     * Used for parameterized custom selector
     */
    public static final String CONTAINS_KEY = "text";
    /**
     * Used for parameterized custom selector
     */
    public static final String CASE_KEY = "casesensitive";
    /**
     * Used for parameterized custom selector
     */
    public static final String WHITESPACE_KEY = "ignorewhitespace";


    /**
     * Creates a new <code>ContainsSelector</code> instance.
     */
    public ContainsSelector()
    {
    }

    /**
     * @return a string describing this object
     */
    public String toString()
    {
        StringBuffer buf = new StringBuffer("{containsselector text: ");
        buf.append(contains);
        buf.append(" casesensitive: ");
        if (casesensitive)
        {
            buf.append("true");
        }
        else
        {
            buf.append("false");
        }
        buf.append(" ignorewhitespace: ");
        if (ignorewhitespace)
        {
            buf.append("true");
        }
        else
        {
            buf.append("false");
        }
        buf.append("}");
        return buf.toString();
    }

    /**
     * The string to search for within a file.
     *
     * @param contains the string that a file must contain to be selected.
     */
    public void setText(String contains)
    {
        this.contains = contains;
    }

    /**
     * Whether to ignore case in the string being searched.
     *
     * @param casesensitive whether to pay attention to case sensitivity
     */
    public void setCasesensitive(boolean casesensitive)
    {
        this.casesensitive = casesensitive;
    }

    /**
     * Whether to ignore whitespace in the string being searched.
     *
     * @param ignorewhitespace whether to ignore any whitespace
     *                         (spaces, tabs, etc.) in the searchstring
     */
    public void setIgnorewhitespace(boolean ignorewhitespace)
    {
        this.ignorewhitespace = ignorewhitespace;
    }

    /**
     * When using this as a custom selector, this method will be called.
     * It translates each parameter into the appropriate setXXX() call.
     *
     * @param parameters the complete set of parameters for this selector
     */
    public void setParameters(Parameter[] parameters)
    {
        super.setParameters(parameters);
        if (parameters != null)
        {
            for (Parameter parameter : parameters)
            {
                String paramname = parameter.getName();
                if (CONTAINS_KEY.equalsIgnoreCase(paramname))
                {
                    setText(parameter.getValue());
                }
                else if (CASE_KEY.equalsIgnoreCase(paramname))
                {
                    setCasesensitive(Boolean.parseBoolean(parameter.getValue()));
                }
                else if (WHITESPACE_KEY.equalsIgnoreCase(paramname))
                {
                    setIgnorewhitespace(Boolean.parseBoolean(parameter.getValue()));
                }
                else
                {
                    setError("Invalid parameter " + paramname);
                }
            }
        }
    }

    /**
     * Checks to make sure all settings are kosher. In this case, it
     * means that the pattern attribute has been set.
     */
    public void verifySettings()
    {
        if (contains == null)
        {
            setError("The text attribute is required");
        }
    }

    /**
     * The heart of the matter. This is where the selector gets to decide
     * on the inclusion of a file in a particular fileset.
     *
     * @param basedir  the base directory the scan is being done from
     * @param filename is the name of the file to check
     * @param file     is a java.io.File object the selector can use
     * @return whether the file should be selected or not
     */
    public boolean isSelected(InstallData idata, File basedir, String filename, File file)
            throws Exception
    {
        // throw BuildException on error
        validate();

        if (file.isDirectory())
        {
            return true;
        }

        String userstr = contains;
        if (!casesensitive)
        {
            userstr = contains.toLowerCase();
        }
        if (ignorewhitespace)
        {
            userstr = SelectorUtils.removeWhitespace(userstr);
        }
        BufferedReader in = null;
        try
        {
            in = new BufferedReader(new InputStreamReader(
                    new FileInputStream(file)));
            String teststr = in.readLine();
            while (teststr != null)
            {
                if (!casesensitive)
                {
                    teststr = teststr.toLowerCase();
                }
                if (ignorewhitespace)
                {
                    teststr = SelectorUtils.removeWhitespace(teststr);
                }
                if (teststr.indexOf(userstr) > -1)
                {
                    return true;
                }
                teststr = in.readLine();
            }
            return false;
        }
        catch (IOException ioe)
        {
            throw new Exception("Could not read file " + filename);
        }
        finally
        {
            if (in != null)
            {
                try
                {
                    in.close();
                }
                catch (Exception e)
                {
                    throw new Exception("Could not close file "
                            + filename);
                }
            }
        }
    }

}

